Rather than point you to the sources you seek, I would offer a word of caution.
It is hard to get the core issues because this has become such a politically divided issue. I have yet find a site that doesn't have some sort of bias.
There is a great deal of hate on both sides of the debate. Because of this, the sides won't listen to each other and this leads to misunderstandings of definitions. For example, both sides of the debate generally agree that the Earth has warmed, but the AGW crowd is convinced that the skeptics are denying the fact that temperatures have risen.
There are a lot of appeals to authority. Words like "consensus" are thrown around a lot. Ignore that.
You seem to be a sincere seeker of truth. You will likely find yourself swinging from one side to the other as you learn additional things. That's normal. Keep with it and you'll eventually find an answer that satisfies you.
Gnissem writes: Where can a reasonably educated layperson read the pro and con evidence for global warming? Maybe even with real data that can be understood by someone who remembers their college math and physics. I'm asked all the time by friends and relatives for my opinion on global warming, and I always hesitate to answer. Yes it seems like far more 'experts' believe it is real than not, but I don't want to just parrot the words of someone else. I'd like to try to decide for myself. Everything I have read is either far too simple, or written for atmospheric scientists, or so clearly approaching the evidence with a strong pre-existing bias. Isn't there anyone who, like me, hasn't made up their mind and has reviewed and presented the evidence before coming to a conclusion?
I know what you mean about the irresponsible user, and certainly that will happen. But consider the scenario you describe. There is no "root" user to log in as such on Ubuntu. Certainly some clowns will write apps to exploit users' stupidity, but Ubuntu (among others) are so much a part of the F/OSS community that said clowns should be kept in check pretty well. I'm not saying exploits won't happen, but I do believe that they will be far less of a problem than Windows users are used to.
If you are interested in AV for Linux, I have a bridge I'd like to sell you. I grow weary of the myth that Windows has viruses only because it dominates the market. Unix-like operating systems are simply built better. You have to work really hard to get those OSes to be insecure. Please research the matter, then come back and post your apology.
For a long time Microsoft was a growth stock, and their P/E of 30 reflected that. Investors really expected that to continue as their server "products" displaced Unix, foreign markets began to flourish, and embedded products opened up to them. I personally believe that their stock has stayed put for so long simply because all three of these growth strategies were stymied, most often by Linux and/or other F/OSS.
You got a "+5 Insightful," and I would agree with the mods, but your reply was non sequitur to the GP. His/her point was that the time and money investment will likely not pay for itself. Your bottom line was, well, this: "The bottom line is that you go back to school because you love the subject." That's fine, but that wasn't what the GP was saying.
I will add as well that going back to school is not the only way to pursue an interest in a loved subject.